Proximity switches are used in a variety of machine applications, such as for monitoring the location of moving parts of various devices. Very often, the moving part to be monitored is located within a casing or cover portion of a device, or in another similarly remote position. For machine design and safety considerations, moving parts are generally shielded in one way or another so as to be effectively isolated from inadvertent access by operators, assemblers and the like. Proximity switches, on the other hand, must be located adjacent moving parts to accurately monitor location and travel thereof, and must often be adjusted during assembly and/or operation. Accordingly, adjustment of proximity switches has often been inconvenient and unwieldy.
Proximity switches themselves are generally cylindrical electrical devices, with a magnetic flux at one end for detection of a moving member. In some applications, machine members may move axially of the cylindrical switch, i.e., toward and away from the detection end or face. Many such switches have finely-threaded portions to facilitate attachment and axial adjustment of the switch, and lock nuts to secure the switch once positioned.
In other applications, a machine member may move radially of the switch, e.g., across the detection face. It is a more difficult task to adjust the switch radially, with precision. Adjustable mounting plates have been used, but very fine adjustments (e.g., on the order of several thousandths of an inch) are difficult to consistently obtain, when an assembler has to directly slide a mounting plate. The provision of fine adjustment screws and an adjusting bracket adds to the complexity of the machine assembly, and overall cost. Heretofore, there has not been available a relatively simple adjustment device or arrangement which provided the ability to make precise, radial adjustments of a proximity switch in a convenient, reliable manner